At elevated speeds (higher than 80 kmh/50 mph or so) and while going round a right-handed bend (at higher than 65 kmh/40 mph) the car makes a noise. I'm pretty sure it's the differential and here's my question:From which car is it possible to take the diff from and mount it to my current 3.2 V6 (auto box)? Haynes says that from '98 and up every 4 pot and 3.0 V6 autos had a final drive ratio of 3.9:1. Also up to '98 2.5 V6 auto and every 4 pot had a 3.9:1 diff. Are the mechanics inside a 4pot diff as strong as in a 3.0 V6?And does anyone know what is the final drive of a 3.2 auto sold in the year 2002 in Germany?

I did suspect the wheel bearings as well, but they were checked on the repair lift. Didn't hear any noise once the wheels were turning (well as fast as a person can make them turn once stationary). And yes it's quite quiet at a left-hander. Are there any others ways to test whether the bearings are shot or not?Also it turned out the diff had lost some oil which was replaced (the old oil had some metal filings in it unfortunately) and now it makes a noise at higher speeds. Before it made a noise at 30-40 kmh (~20-25 mph) as well. That's where the question arises about the diffs, metal in oil is almost always a bad thing. Also the diff is slightly covered in oil, should change it sometime anyway.So for the sake of an argument lets rule out the bearings for now. I'm going to get them checked again though.

I had a noise from the rear of my 2.5 estate; diff or bearing, I wondered. I parked the vehicle above my pit, supported the rear axle on axle stands, started the engine with 4th gear engaged, and descended into the pit. The noise was clearly coming from the differential.

. That's a really good idea.Though I am still hoping that someone would have information about which differential would fit to my car apart from another 3.2 V6. The latter are quite rare where I live, I don't expect one to be scrapped here so I could buy an identical one.ORIf someone reading this knows someone who is selling a leak- and noise-free LSD diff for 3.2 Omega automatic and is willing to post it to me to Estonia (or someone who is about to take on a journey through Europe and by some chance end up in Estonia), let me know.

I had a noise from the rear of my 2.5 estate; diff or bearing, I wondered. I parked the vehicle above my pit, supported the rear axle on axle stands, started the engine with 4th gear engaged, and descended into the pit. The noise was clearly coming from the differential.

. That's a really good idea.Though I am still hoping that someone would have information about which differential would fit to my car apart from another 3.2 V6. The latter are quite rare where I live, I don't expect one to be scrapped here so I could buy an identical one.ORIf someone reading this knows someone who is selling a leak- and noise-free LSD diff for 3.2 Omega automatic and is willing to post it to me to Estonia (or someone who is about to take on a journey through Europe and by some chance end up in Estonia), let me know.

If its an Auto you will need a 3.9 Diff, doesn't matter if its from a V6 or 4 Pot Omega, all the 3.9 are the same except in LSD form.

Working LSD Diff for the Omega are as rare as Hens Teeth now. I do have one from an Ex Police (3.9 Ratio), full working, about 60K miles old. Let me think about it.

. That's a really good idea.Though I am still hoping that someone would have information about which differential would fit to my car apart from another 3.2 V6. The latter are quite rare where I live, I don't expect one to be scrapped here so I could buy an identical one.ORIf someone reading this knows someone who is selling a leak- and noise-free LSD diff for 3.2 Omega automatic and is willing to post it to me to Estonia (or someone who is about to take on a journey through Europe and by some chance end up in Estonia), let me know.

If its an Auto you will need a 3.9 Diff, doesn't matter if its from a V6 or 4 Pot Omega, all the 3.9 are the same except in LSD form.

Working LSD Diff for the Omega are as rare as Hens Teeth now. I do have one from an Ex Police (3.9 Ratio), full working, about 60K miles old. Let me think about it.

. That's a really good idea.Though I am still hoping that someone would have information about which differential would fit to my car apart from another 3.2 V6. The latter are quite rare where I live, I don't expect one to be scrapped here so I could buy an identical one.ORIf someone reading this knows someone who is selling a leak- and noise-free LSD diff for 3.2 Omega automatic and is willing to post it to me to Estonia (or someone who is about to take on a journey through Europe and by some chance end up in Estonia), let me know.

If its an Auto you will need a 3.9 Diff, doesn't matter if its from a V6 or 4 Pot Omega, all the 3.9 are the same except in LSD form.

Working LSD Diff for the Omega are as rare as Hens Teeth now. I do have one from an Ex Police (3.9 Ratio), full working, about 60K miles old. Let me think about it.

GM diff oil + GM's LS additive from dealer seems to be best and not even expensive.I think it is common that diff oils never been changed and then they are starting to make noise or fail. Change oil and LS additive first, because it is cheapest and probably fixes the problem.

After (or before) that check for play at rear bearings.

I have changed both rear bearings:- right side had play but no noise from it (~240 tkm)- left side, 3 years after right side replacement, had no play but very bad noise just as yours (~320 tkm). Felt and sounded like someone was hammer drilling at trunk, highest sound was at 80 km/h speed.